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McCord B, Day RM. Influence of Inflammatory Cytokines IL-1 β and IFN γ on Sarcoplasmic Aggregation of p62 and TDP-43 in Myotubes. Mediators Inflamm 2023; 2023:9018470. [PMID: 37731843 PMCID: PMC10509004 DOI: 10.1155/2023/9018470] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2023] [Revised: 08/10/2023] [Accepted: 08/19/2023] [Indexed: 09/22/2023] Open
Abstract
Skeletal muscle of patients with sporadic inclusion body myositis (sIBM) presents with inflammation, including upregulation of inflammatory cytokines such as interferon γ (IFNγ). Non-inflammatory features are also observed, like the sarcoplasmic accumulation of proteins including TDP-43 and p62. This study aimed to investigate the effect of IFNγ and interleukin 1-β (IL-1β) on TDP-43 and p62 aggregation in vitro. Primary human myotubes were treated with IL-1β (20 ng/mL) and IFNγ (750 ng/mL) separately or combined for 48 hr. Sarcoplasmic TDP-43 aggregates and p62 puncta were assessed using image analysis for size, frequency, and colocalization with each other. Total protein expression of TDP-43, p62 and LC3 was assessed using western blotting. The subcellular localization of TDP-43 was also analyzed using image analysis. Combined IL-1β and IFNγ treatment increased puncta size of p62 compared to control (0.49 ± 0.13 µm2 versus 0.28 ± 0.06 µm2), without affecting puncta frequency or p62 expression but with an increased LC3II/LC3I ratio, suggesting autophagic alterations. IL-1β or IFNγ did not alter p62 puncta size or frequency, suggesting a combined insult of multiple inflammatory mediators is necessary to cause p62 alterations. IL-1β increased p62 protein expression in an autophagy-independent manner. None of the cytokine treatments affected TDP-43 protein expression, size, or frequency of TDP-43 aggregates or localization, suggesting IL-1β and IFNγ may influence TDP-43 processing in human skeletal muscle cells. TDP-43 was localized to the sarcoplasm under control conditions, suggesting this may not be a pathological feature. Overall, sIBM-like TDP-43/p62 features were not triggered by IL-1β and/or IFNγ.
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Affiliation(s)
- Bryony McCord
- Centre for Precision Healthcare, UCL Division of Medicine, University College London, London WC1E 6JF, UK
| | - Richard M. Day
- Centre for Precision Healthcare, UCL Division of Medicine, University College London, London WC1E 6JF, UK
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2
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Lee EJ, Neppl RL. Influence of Age on Skeletal Muscle Hypertrophy and Atrophy Signaling: Established Paradigms and Unexpected Links. Genes (Basel) 2021; 12:genes12050688. [PMID: 34063658 PMCID: PMC8147613 DOI: 10.3390/genes12050688] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2021] [Revised: 04/26/2021] [Accepted: 04/27/2021] [Indexed: 12/16/2022] Open
Abstract
Skeletal muscle atrophy in an inevitable occurrence with advancing age, and a consequence of disease including cancer. Muscle atrophy in the elderly is managed by a regimen of resistance exercise and increased protein intake. Understanding the signaling that regulates muscle mass may identify potential therapeutic targets for the prevention and reversal of muscle atrophy in metabolic and neuromuscular diseases. This review covers the major anabolic and catabolic pathways that regulate skeletal muscle mass, with a focus on recent progress and potential new players.
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3
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Abstract
PURPOSE OF REVIEW This article reviews the clinical, laboratory, and histopathologic features of sporadic inclusion body myositis (IBM) and explores its pathogenic overlap with inherited myopathies that have IBM-like pathology. RECENT FINDINGS Sporadic IBM is the most common acquired muscle disease in patients older than 50 years of age and is becoming more prevalent because of the increasing age of the population, the emerging development of more inclusive diagnostic criteria, and the advent of a diagnostic autoantibody. No effective therapy is known, and the pathogenic mechanism remains unclear. Some pathogenic insight can be gleaned from other myopathies with pathologic similarities or hereditary inclusion body myopathies. Although clinically distinct from sporadic IBM, preclinical models of hereditary inclusion body myopathy have offered an opportunity to move some therapies toward clinical development. SUMMARY Patients with sporadic IBM experience significant morbidity, and the disease is associated with a large unmet medical need. As therapies are developed, improved diagnosis will be essential. Early diagnosis relies on awareness, clinical history, physical examination, laboratory features, and appropriate muscle biopsy processing. Future research is needed to understand the natural history, identify genetic risk factors, and validate biomarkers to track disease progression. These steps are essential as we move toward therapeutic interventions.
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Ciryam P, Antalek M, Cid F, Tartaglia GG, Dobson CM, Guettsches AK, Eggers B, Vorgerd M, Marcus K, Kley RA, Morimoto RI, Vendruscolo M, Weihl CC. A metastable subproteome underlies inclusion formation in muscle proteinopathies. Acta Neuropathol Commun 2019; 7:197. [PMID: 31796104 PMCID: PMC6891963 DOI: 10.1186/s40478-019-0853-9] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2019] [Accepted: 11/21/2019] [Indexed: 01/20/2023] Open
Abstract
Protein aggregation is a pathological feature of neurodegenerative disorders. We previously demonstrated that protein inclusions in the brain are composed of supersaturated proteins, which are abundant and aggregation-prone, and form a metastable subproteome. It is not yet clear, however, whether this phenomenon is also associated with non-neuronal protein conformational disorders. To respond to this question, we analyzed proteomic datasets from biopsies of patients with genetic and acquired protein aggregate myopathy (PAM) by quantifying the changes in composition, concentration and aggregation propensity of proteins in the fibers containing inclusions and those surrounding them. We found that a metastable subproteome is present in skeletal muscle from healthy patients. The expression of this subproteome escalate as proteomic samples are taken more proximal to the pathologic inclusion, eventually exceeding its solubility limits and aggregating. While most supersaturated proteins decrease or maintain steady abundance across healthy fibers and inclusion-containing fibers, proteins within the metastable subproteome rise in abundance, suggesting that they escape regulation. Taken together, our results show in the context of a human conformational disorder that the supersaturation of a metastable subproteome underlies widespread aggregation and correlates with the histopathological state of the tissue.
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5
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Fuqua JD, Mere CP, Kronemberger A, Blomme J, Bae D, Turner KD, Harris MP, Scudese E, Edwards M, Ebert SM, de Sousa LGO, Bodine SC, Yang L, Adams CM, Lira VA. ULK2 is essential for degradation of ubiquitinated protein aggregates and homeostasis in skeletal muscle. FASEB J 2019; 33:11735-11745. [PMID: 31361156 PMCID: PMC6902739 DOI: 10.1096/fj.201900766r] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Basal protein turnover, which largely relies on the degradation of ubiquitinated substrates, is instrumental for maintenance of muscle mass and function. However, the regulation of ubiquitinated protein degradation in healthy, nonatrophying skeletal muscle is still evolving, and potential tissue-specific modulators remain unknown. Using an unbiased expression analysis of 34 putative autophagy genes across mouse tissues, we identified unc-51 like autophagy activating kinase (Ulk)2, a homolog of the yeast autophagy related protein 1, as particularly enriched in skeletal muscle. Subsequent experiments revealed accumulations of insoluble ubiquitinated protein aggregates associated with the adaptors sequestosome 1 (SQSTM1, also known as p62) and next to breast cancer type 1 susceptibility protein gene 1 protein (NBR1) in adult muscles with ULK2 deficiency. ULK2 deficiency also led to impaired muscle force and caused myofiber atrophy and degeneration. These features were not observed in muscles with deficiency of the ULK2 paralog, ULK1. Furthermore, short-term ULK2 deficiency did not impair autophagy initiation, autophagosome to lysosome fusion, or protease activities of the lysosome and proteasome. Altogether, our results indicate that skeletal muscle ULK2 has a unique role in basal selective protein degradation by stimulating the recognition and proteolytic sequestration of insoluble ubiquitinated protein aggregates associated with p62 and NBR1. These findings have potential implications for conditions of poor protein homeostasis in muscles as observed in several myopathies and aging.-Fuqua, J. D., Mere, C. P., Kronemberger, A., Blomme, J., Bae, D., Turner, K. D., Harris, M. P., Scudese, E., Edwards, M., Ebert, S. M., de Sousa, L. G. O., Bodine, S. C., Yang, L., Adams, C. M., Lira, V. A. ULK2 is essential for degradation of ubiquitinated protein aggregates and homeostasis in skeletal muscle.
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Affiliation(s)
- Jordan D Fuqua
- Department of Health and Human Physiology, The University of Iowa, Iowa City, Iowa, USA
| | - Caleb P Mere
- Department of Health and Human Physiology, The University of Iowa, Iowa City, Iowa, USA
| | - Ana Kronemberger
- Department of Health and Human Physiology, The University of Iowa, Iowa City, Iowa, USA
| | - Jay Blomme
- Department of Health and Human Physiology, The University of Iowa, Iowa City, Iowa, USA
| | - Dam Bae
- Department of Health and Human Physiology, The University of Iowa, Iowa City, Iowa, USA
| | - Kristen D Turner
- Department of Health and Human Physiology, The University of Iowa, Iowa City, Iowa, USA
| | - Matthew P Harris
- Department of Health and Human Physiology, The University of Iowa, Iowa City, Iowa, USA
| | - Estevão Scudese
- Department of Health and Human Physiology, The University of Iowa, Iowa City, Iowa, USA.,Nursing and Biosciences, Federal University of the State of Rio de Janeiro, Rio de Janeiro, Brazil
| | - Mitchell Edwards
- Department of Health and Human Physiology, The University of Iowa, Iowa City, Iowa, USA
| | - Scott M Ebert
- Department of Molecular Physiology and Biophysics, The University of Iowa, Iowa City, Iowa, USA
| | - Luís G O de Sousa
- Department of Internal Medicine, The University of Iowa, Iowa City, Iowa, USA
| | - Sue C Bodine
- Department of Internal Medicine, The University of Iowa, Iowa City, Iowa, USA.,Fraternal Order of Eagles Diabetes Research Center, The University of Iowa, Iowa City, Iowa, USA
| | - Ling Yang
- Fraternal Order of Eagles Diabetes Research Center, The University of Iowa, Iowa City, Iowa, USA.,Department of Anatomy and Cell Biology, The University of Iowa, Iowa City, Iowa, USA.,Pappajohn Biomedical Institute, The University of Iowa, Iowa City, Iowa, USA
| | - Christopher M Adams
- Department of Molecular Physiology and Biophysics, The University of Iowa, Iowa City, Iowa, USA.,Department of Internal Medicine, The University of Iowa, Iowa City, Iowa, USA.,Fraternal Order of Eagles Diabetes Research Center, The University of Iowa, Iowa City, Iowa, USA.,Pappajohn Biomedical Institute, The University of Iowa, Iowa City, Iowa, USA.,Obesity Research and Education Initiative, The University of Iowa, Iowa City, Iowa, USA
| | - Vitor A Lira
- Department of Health and Human Physiology, The University of Iowa, Iowa City, Iowa, USA.,Fraternal Order of Eagles Diabetes Research Center, The University of Iowa, Iowa City, Iowa, USA.,Pappajohn Biomedical Institute, The University of Iowa, Iowa City, Iowa, USA.,Obesity Research and Education Initiative, The University of Iowa, Iowa City, Iowa, USA.,François M. Abboud Cardiovascular Research Center, The University of Iowa, Iowa City, Iowa, USA
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6
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Haczkiewicz K, Sebastian A, Piotrowska A, Misterska-Skóra M, Hałoń A, Skoczyńska M, Sebastian M, Wiland P, Dzięgiel P, Podhorska-Okołów M. Immunohistochemical and ultrastructural analysis of sporadic inclusion body myositis: a case series. Rheumatol Int 2018; 39:1291-1301. [PMID: 30535925 DOI: 10.1007/s00296-018-4221-z] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2018] [Accepted: 12/04/2018] [Indexed: 12/18/2022]
Abstract
Sporadic inclusion body myositis (s-IBM) is a progressive, skeletal muscle disease with poor prognosis. However, establishing the final diagnosis is difficult because of the lack of clear biomarkers in the blood serum and very slow development of clinical symptoms. Moreover, most other organs function normally without any disturbance. Here, in patients with this untreatable disease, we have underlined the importance of immunohistochemical and ultrastructural assessment of skeletal muscle in patients diagnosed with s-IBM. The goal of this study was to identify the distribution of specific antigens and to determine morphological features in order to localize pathological protein aggregates, rimmed vacuoles, and loss of myofibrils, which are key elements in the diagnosis of s-IBM. All studied patients were between 48 and 83 years of age and were hospitalized in the Department of Rheumatology and Internal Medicine between 2011 and 2016. Anamneses revealed an accelerated progression of muscle atrophy, weakness of limb muscles, and difficulties with climbing stairs. Based on histopathology and transmission electron microscopy examination, inflammatory infiltrations consisting of mononuclear cells, severe atrophy and focal necrosis of myofibers, splitting of myofilaments, myelinoid bodies and rimmed vacuoles were observed. Primary antibodies directed against CD3, CD8, CD68, cN1A, beta-amyloid, Tau protein and apolipoprotein B made it possible to identify types of cells within infiltrations as well as the protein deposits within myofibers. Using a combination of immunohistochemistry and electron microscopy methods, we were able to establish the correct final diagnosis and to implement a specific treatment to inhibit disease progression.
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Affiliation(s)
- Katarzyna Haczkiewicz
- Division of Histology and Embryology, Department of Human Morphology and Embryology, Wroclaw Medical University, Chałubińskiego Street 6a, 50-368, Wrocław, Poland.
| | - Agata Sebastian
- Department of Rheumatology and Internal Medicine, Wroclaw Medical University, Borowska Street 213, 50-556, Wrocław, Poland
| | - Aleksandra Piotrowska
- Division of Histology and Embryology, Department of Human Morphology and Embryology, Wroclaw Medical University, Chałubińskiego Street 6a, 50-368, Wrocław, Poland
| | - Maria Misterska-Skóra
- Department of Rheumatology and Internal Medicine, Wroclaw Medical University, Borowska Street 213, 50-556, Wrocław, Poland
| | - Agnieszka Hałoń
- Department of Pathomorphology, Wroclaw Medical University, Borowska Street 213, 50-556, Wrocław, Poland
| | - Marta Skoczyńska
- Department of Rheumatology and Internal Medicine, Wroclaw Medical University, Borowska Street 213, 50-556, Wrocław, Poland
| | - Maciej Sebastian
- Department of Minimally Invasive Surgery and Proctology, Wroclaw Medical University, Borowska Street 213, 50-556, Wrocław, Poland
| | - Piotr Wiland
- Department of Rheumatology and Internal Medicine, Wroclaw Medical University, Borowska Street 213, 50-556, Wrocław, Poland
| | - Piotr Dzięgiel
- Division of Histology and Embryology, Department of Human Morphology and Embryology, Wroclaw Medical University, Chałubińskiego Street 6a, 50-368, Wrocław, Poland
| | - Marzenna Podhorska-Okołów
- Division of Histology and Embryology, Department of Human Morphology and Embryology, Wroclaw Medical University, Chałubińskiego Street 6a, 50-368, Wrocław, Poland
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7
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Tawara N, Yamashita S, Kawakami K, Kurashige T, Zhang Z, Tasaki M, Yamamoto Y, Nishikami T, Doki T, Zhang X, Matsuo Y, Kimura E, Tawara A, Maeda Y, Hauschka SD, Maruyama H, Ando Y. Muscle-dominant wild-type TDP-43 expression induces myopathological changes featuring tubular aggregates and TDP-43-positive inclusions. Exp Neurol 2018; 309:169-180. [PMID: 30130494 DOI: 10.1016/j.expneurol.2018.08.006] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2018] [Revised: 07/30/2018] [Accepted: 08/15/2018] [Indexed: 11/15/2022]
Abstract
Muscle histology of sporadic inclusion body myositis (sIBM) demonstrates inflammatory findings and degenerative features including accumulation of TAR DNA-binding protein of 43 kDa (TDP-43). However, whether sarcoplasmic accumulation of TDP-43 is a primary trigger of muscle degeneration or a secondary event resulting from muscle degeneration in the pathophysiology of sIBM remained unclear. Our study aimed to discover whether muscle-dominant expression of TDP-43 is a primary cause of muscle degeneration. We generated several lines of wild-type TDP-43 transgenic mice driven by a creatine kinase 8 promoter, and analyzed the phenotypes via biochemical, histological, and proteomic techniques. The mice showed increased serum levels of myogenic enzymes. Muscle histology demonstrated myopathic changes including fiber size variation, abundant tubular aggregates, and TDP-43 aggregation with upregulation of endoplasmic reticulum (ER) stress. Proteomic analysis with aggregated materials in degenerative myofibers identified increased sarcoplasmic reticulum (SR)/ER-resident proteins that regulated calcium homeostasis, as well as cytosolic 5'-nucleotidase 1A. Muscle-dominant wild-type TDP-43 expression indeed caused myotoxicity featuring tubular aggregates and TDP-43-positive inclusions. Our observation suggested that TDP-43 aggregates might not be sufficient to trigger the pathogenesis of sIBM although myofiber sarcoplasmic aggregation of TDP-43 led to myofiber degeneration via ER stress and possibly calcium dysregulation, independently of inflammatory process.
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Affiliation(s)
- Nozomu Tawara
- Department of Neurology, Graduate School of Medical Sciences, Kumamoto University, 1-1-1 Honjo, Chuo-ku, Kumamoto 860-8556, Japan
| | - Satoshi Yamashita
- Department of Neurology, Graduate School of Medical Sciences, Kumamoto University, 1-1-1 Honjo, Chuo-ku, Kumamoto 860-8556, Japan.
| | - Kensuke Kawakami
- Department of Neurology, Graduate School of Medical Sciences, Kumamoto University, 1-1-1 Honjo, Chuo-ku, Kumamoto 860-8556, Japan
| | - Takashi Kurashige
- Department of Neurology, National Hospital Organization Kure Medical Centre, 3-1 Aoyama-cho, Kure, Hiroshima 737-0023, Japan; Department of Clinical Neuroscience and Therapeutics, Hiroshima University Graduate School of Biomedical and Health Sciences, 1-2-3 Kasumi, Minami-ku, Hiroshima 734-8551, Japan
| | - Ziwei Zhang
- Department of Neurology, Graduate School of Medical Sciences, Kumamoto University, 1-1-1 Honjo, Chuo-ku, Kumamoto 860-8556, Japan
| | - Masayoshi Tasaki
- Department of Neurology, Graduate School of Medical Sciences, Kumamoto University, 1-1-1 Honjo, Chuo-ku, Kumamoto 860-8556, Japan
| | - Yasuhiro Yamamoto
- Department of Neurology, Graduate School of Medical Sciences, Kumamoto University, 1-1-1 Honjo, Chuo-ku, Kumamoto 860-8556, Japan
| | - Tomo Nishikami
- Department of Neurology, Graduate School of Medical Sciences, Kumamoto University, 1-1-1 Honjo, Chuo-ku, Kumamoto 860-8556, Japan
| | - Tsukasa Doki
- Department of Neurology, Graduate School of Medical Sciences, Kumamoto University, 1-1-1 Honjo, Chuo-ku, Kumamoto 860-8556, Japan
| | - Xiao Zhang
- Department of Neurology, Graduate School of Medical Sciences, Kumamoto University, 1-1-1 Honjo, Chuo-ku, Kumamoto 860-8556, Japan
| | - Yoshimasa Matsuo
- Department of Neurology, Graduate School of Medical Sciences, Kumamoto University, 1-1-1 Honjo, Chuo-ku, Kumamoto 860-8556, Japan
| | - En Kimura
- Translational Medical Center, National Center of Neurology and Psychiatry, 4-1-1 Ogawahigashi, Kodaira 187-8551, Japan
| | - Akie Tawara
- Department of Neurology, Graduate School of Medical Sciences, Kumamoto University, 1-1-1 Honjo, Chuo-ku, Kumamoto 860-8556, Japan
| | - Yasushi Maeda
- Department of Clinical Research, and Department of Neurology, National Hospital Organization Kumamoto Saishunso National Hospital, 2659 Suya, Koshi, Kumamoto 861-1196, Japan
| | - Stephen D Hauschka
- Department of Biochemistry, University of Washington, 1705 NE Pacific St., Seattle, WA 98195-7350, USA
| | - Hirofumi Maruyama
- Department of Clinical Neuroscience and Therapeutics, Hiroshima University Graduate School of Biomedical and Health Sciences, 1-2-3 Kasumi, Minami-ku, Hiroshima 734-8551, Japan
| | - Yukio Ando
- Department of Neurology, Graduate School of Medical Sciences, Kumamoto University, 1-1-1 Honjo, Chuo-ku, Kumamoto 860-8556, Japan
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8
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Papadopoulos C, Meyer H. Detection and Clearance of Damaged Lysosomes by the Endo-Lysosomal Damage Response and Lysophagy. Curr Biol 2018; 27:R1330-R1341. [PMID: 29257971 DOI: 10.1016/j.cub.2017.11.012] [Citation(s) in RCA: 121] [Impact Index Per Article: 20.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Lysosomal membrane permeabilization or lysosomal rupture is recognized as a common and severe stress condition relevant for infection, cellular degeneration and cancer. However, the cellular response mechanisms that protect cells from the consequences of lysosomal damage and ensure lysosomal quality control and homeostasis have only recently been explored. Key elements of this response involve the specific sensing of the damage followed by extensive modification of the organelles with ubiquitin to mark them for clearance by selective macroautophagy, termed lysophagy. Efficient lysophagy is ensured by additional layers of regulation, including modulation by the ubiquitin-directed AAA-ATPase VCP/p97. Lysophagy shares many features with mitophagy, the macroautophagic removal of damaged mitochondria. This review aims to gather available data from different fields and to define the key steps necessary for sensing and subsequent clearance of damaged lysosomes. We conclude with a discussion of disease implications with a focus on neurodegeneration.
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Affiliation(s)
- Chrisovalantis Papadopoulos
- Molecular Biology I, Centre for Medical Biotechnology, Faculty of Biology, University of Duisburg-Essen, 45141 Essen, Germany.
| | - Hemmo Meyer
- Molecular Biology I, Centre for Medical Biotechnology, Faculty of Biology, University of Duisburg-Essen, 45141 Essen, Germany.
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9
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Weihl CC, Mammen AL. Sporadic inclusion body myositis - a myodegenerative disease or an inflammatory myopathy. Neuropathol Appl Neurobiol 2018; 43:82-91. [PMID: 28111778 DOI: 10.1111/nan.12384] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2016] [Revised: 01/17/2017] [Accepted: 01/23/2017] [Indexed: 12/29/2022]
Abstract
Sporadic inclusion body myositis (sIBM) is an insidious late-onset progressive myopathy that typically affects patients over the age of 50. Clinically, patients develop a characteristic pattern of weakness that affects the forearm flexors and knee extensors. Muscle biopsy, often utilized in the diagnosis, demonstrates a chronic myopathy with mixed pathologies harbouring intramyofiber protein inclusions and endomysial inflammation. The co-existence of these pathologic features (that is, inflammation and protein aggregation) has divided the field of sIBM research into two opposing (albeit slowly unifying) camps regarding disease pathogenesis. The present review explores the recent evidence supporting these distinct pathogenic mechanisms. Future therapies that are designed to target both aspects of sIBM pathologies will likely be necessary to treat sIBM.
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Affiliation(s)
- C C Weihl
- Department of Neurology and Hope Center for Neurological Diseases, Washington University School of Medicine, Saint Louis, MO, USA
| | - A L Mammen
- Muscle Disease Unit, Laboratory of Muscle Stem Cells and Gene Expression, National Institute of Arthritis and Musculoskeletal and Skin Diseases, National Institutes of Health, Bethesda, MD, USA
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10
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Sporadic Inclusion Body Myositis: MRI Findings and Correlation With Clinical and Functional Parameters. AJR Am J Roentgenol 2017; 209:1340-1347. [DOI: 10.2214/ajr.17.17849] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
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11
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Güttsches AK, Brady S, Krause K, Maerkens A, Uszkoreit J, Eisenacher M, Schreiner A, Galozzi S, Mertens-Rill J, Tegenthoff M, Holton JL, Harms MB, Lloyd TE, Vorgerd M, Weihl CC, Marcus K, Kley RA. Proteomics of rimmed vacuoles define new risk allele in inclusion body myositis. Ann Neurol 2017; 81:227-239. [PMID: 28009083 DOI: 10.1002/ana.24847] [Citation(s) in RCA: 49] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2016] [Revised: 11/22/2016] [Accepted: 12/11/2016] [Indexed: 12/29/2022]
Abstract
OBJECTIVE Sporadic inclusion body myositis (sIBM) pathogenesis is unknown; however, rimmed vacuoles (RVs) are a constant feature. We propose to identify proteins that accumulate within RVs. METHODS RVs and intact myofibers were laser microdissected from skeletal muscle of 18 sIBM patients and analyzed by a sensitive mass spectrometry approach using label-free spectral count-based relative protein quantification. Whole exome sequencing was performed on 62 sIBM patients. Immunofluorescence was performed on patient and mouse skeletal muscle. RESULTS A total of 213 proteins were enriched by >1.5 -fold in RVs compared to controls and included proteins previously reported to accumulate in sIBM tissue or when mutated cause myopathies with RVs. Proteins associated with protein folding and autophagy were the largest group represented. One autophagic adaptor protein not previously identified in sIBM was FYCO1. Rare missense coding FYCO1 variants were present in 11.3% of sIBM patients compared with 2.6% of controls (p = 0.003). FYCO1 colocalized at RVs with autophagic proteins such as MAP1LC3 and SQSTM1 in sIBM and other RV myopathies. One FYCO1 variant protein had reduced colocalization with MAP1LC3 when expressed in mouse muscle. INTERPRETATION This study used an unbiased proteomic approach to identify RV proteins in sIBM that included a novel protein involved in sIBM pathogenesis. FYCO1 accumulates at RVs, and rare missense variants in FYCO1 are overrepresented in sIBM patients. These FYCO1 variants may impair autophagic function, leading to RV formation in sIBM patient muscle. FYCO1 functionally connects autophagic and endocytic pathways, supporting the hypothesis that impaired endolysosomal degradation underlies the pathogenesis of sIBM. Ann Neurol 2017;81:227-239.
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Affiliation(s)
- Anne-Katrin Güttsches
- Department of Neurology, Heimer Institute for Muscle Research, University Hospital Bergmannsheil, Ruhr-University Bochum, Bochum, Germany
| | - Stefen Brady
- Department of Neurology, Southmead Hospital, Bristol, United Kingdom
| | - Kathryn Krause
- Department of Neurology, Heimer Institute for Muscle Research, University Hospital Bergmannsheil, Ruhr-University Bochum, Bochum, Germany.,Medizinisches Proteom-Center, Ruhr-University Bochum, Bochum, Germany
| | - Alexandra Maerkens
- Department of Neurology, Heimer Institute for Muscle Research, University Hospital Bergmannsheil, Ruhr-University Bochum, Bochum, Germany.,Medizinisches Proteom-Center, Ruhr-University Bochum, Bochum, Germany
| | - Julian Uszkoreit
- Medizinisches Proteom-Center, Ruhr-University Bochum, Bochum, Germany
| | - Martin Eisenacher
- Medizinisches Proteom-Center, Ruhr-University Bochum, Bochum, Germany
| | - Anja Schreiner
- Department of Neurology, Heimer Institute for Muscle Research, University Hospital Bergmannsheil, Ruhr-University Bochum, Bochum, Germany
| | - Sara Galozzi
- Medizinisches Proteom-Center, Ruhr-University Bochum, Bochum, Germany
| | - Janine Mertens-Rill
- Department of Neurology, Heimer Institute for Muscle Research, University Hospital Bergmannsheil, Ruhr-University Bochum, Bochum, Germany
| | - Martin Tegenthoff
- Department of Neurology, Heimer Institute for Muscle Research, University Hospital Bergmannsheil, Ruhr-University Bochum, Bochum, Germany
| | - Janice L Holton
- MRC Centre for Neuromuscular Diseases, UCL Institute of Neurology, London, United Kingdom.,Department of Molecular Neuroscience, Queen Square Brain Bank, UCL Institute of Neurology, London, United Kingdom
| | | | - Thomas E Lloyd
- Johns Hopkins University School of Medicine, Baltimore, MD
| | - Matthias Vorgerd
- Department of Neurology, Heimer Institute for Muscle Research, University Hospital Bergmannsheil, Ruhr-University Bochum, Bochum, Germany
| | - Conrad C Weihl
- Department of Neurology and Hope Center for Neurological Disorders, Washington University School of Medicine, Saint Louis, MO
| | - Katrin Marcus
- Medizinisches Proteom-Center, Ruhr-University Bochum, Bochum, Germany
| | - Rudolf A Kley
- Department of Neurology, Heimer Institute for Muscle Research, University Hospital Bergmannsheil, Ruhr-University Bochum, Bochum, Germany
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12
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Development and evaluation of a standardized ELISA for the determination of autoantibodies against cN-1A (Mup44, NT5C1A) in sporadic inclusion body myositis. AUTOIMMUNITY HIGHLIGHTS 2016; 7:16. [PMID: 27858337 PMCID: PMC5114199 DOI: 10.1007/s13317-016-0088-8] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/06/2016] [Accepted: 10/25/2016] [Indexed: 01/04/2023]
Abstract
PURPOSE Sporadic inclusion body myositis (sIBM) is an autoimmune degenerative disease of the muscle, with inflammatory infiltrates and inclusion vacuoles. Its pathogenesis is not fully understood and the diagnosis is hampered by its imprecise characteristics, at times indistinguishable from other idiopathic inflammatory myopathies such as polymyositis and dermatomyositis. The diagnosis may be assisted by the detection of autoantibodies targeting Mup44, a skeletal muscle antigen identified as cytosolic 5'-nucleotidase 1A (cN-1A, NT5C1A). A novel standardized anti-cN-1A IgG ELISA was developed and its diagnostic performance was evaluated by two reference laboratories. METHODS Recombinant human full-length cN-1A was expressed and purified, and subsequently utilized to set up a standardized ELISA. To evaluate the novel assay, laboratory A examined sera from North American patients with clinically and pathologically diagnosed definite sIBM (n = 17), suspected sIBM (n = 14), myositis controls (n = 110), non-myositis autoimmune controls (n = 93) and healthy subjects (n = 52). Laboratory B analyzed a Dutch cohort of definite sIBM patients (n = 51) and healthy controls (n = 202). RESULTS Anti-cN-1A reactivity was most frequent in definite sIBM (39.2-47.1%), but absent in biopsy-proven classic polymyositis or dermatomyositis. Overall diagnostic sensitivity and specificity amounted to 35.5 and 96.1% (laboratory A) and 39.2 and 96.5% (laboratory B). CONCLUSIONS Anti-cN-1A autoantibodies were detected by ELISA with moderate sensitivity, but high specificity for sIBM and may therefore help diagnose this infrequent and difficult-to-diagnose myopathy. The novel anti-cN-1A IgG ELISA can improve and accelerate the diagnosis of sIBM using sera where muscle biopsy is delayed or unfeasible.
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13
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Inflammatory myopathies and lymphoma. J Neurol Sci 2016; 369:377-389. [PMID: 27653927 DOI: 10.1016/j.jns.2016.08.060] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2016] [Revised: 08/28/2016] [Accepted: 08/29/2016] [Indexed: 12/18/2022]
Abstract
The inflammatory myopathies comprise a group of immune-mediated muscle diseases. Lymphoma is a term for a variety of lymphatic system malignancies. Autoimmune diseases and lymphoproliferative malignancies share a complex bidirectional relationship. A causal relationship between inflammatory mypathies and lymphoma has not been established. The diagnosis/treatment of inflammatory myopathy usually precedes the detection/diagnosis of lymphoma. Immune system dysregulation presumably underlies the evolution of lymphoma in patients with inflammatory myopathies. Inflammatory activity with chronic B-cell activation and/or antigen stimulation is deemed the major risk factor for lymphoma in patients with autoimmunity. A "paraneoplastic" phenomenon or the effects of immunosuppressive therapy may be alternative immune-based mechanisms. In chronic lymphocytic leukemia immune system disturbance rarely results in non-hematological autoimmune disease, including inflammatory myopathies.
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14
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Hiniker A, Daniels BH, Margeta M. T-Cell-Mediated Inflammatory Myopathies in HIV-Positive Individuals: A Histologic Study of 19 Cases. J Neuropathol Exp Neurol 2016; 75:239-45. [PMID: 26843609 DOI: 10.1093/jnen/nlv023] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
T cell-mediated inflammatory myopathies (polymyositis [PM] and inclusion body myositis [IBM]) sometimes arise in conjunction with HIV infection; however, it is not understood whether PM and IBM arising in the context of HIV (HIV-PM and HV-IBM) differ from PM and IBM arising sporadically in HIV-negative individuals (sPM and sIBM). Here, we report the largest series of T cell-mediated inflammatory myopathies from HIV-infected patients (19 biopsies from 15 subjects); 5 cases were pathologically classified as PM (HIV-PM) and 14 as IBM (HIV-IBM). As with sporadic cases, quantitative immunohistochemistry for LC3, p62, and TDP-43 showed significantly greater percentage of stained fibers (% FS) in HIV-IBM compared to HIV-PM samples; however, there was no significant difference in % FS for any of the three markers between HIV-associated and sporadic cases. Despite histologic similarities between HIV-IBM and sIBM but in concordance with prior case reports, patients with HIV-IBM were significantly younger at diagnosis than patients with sIBM; in contrast, the mean age of HIV-PM and sPM patients was not significantly different. In summary, HIV-PM and HIV-IBM are morphologically similar to sPM and sIBM; thus, it remains unclear why patients with HIV-IBM, in contrast to patients with sIBM, sometimes show clinical improvement in response to immunosuppressive therapy.
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Affiliation(s)
- Annie Hiniker
- From the Department of Pathology, University of California San Francisco, San Francisco, California
| | - Brianne H Daniels
- From the Department of Pathology, University of California San Francisco, San Francisco, California
| | - Marta Margeta
- From the Department of Pathology, University of California San Francisco, San Francisco, California.
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15
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Abstract
Sporadic inclusion body myositis is the most common inflammatory muscle disorder preferentially affecting males over the age of 40 years. Progressive muscle weakness of the finger flexors and quadriceps muscles results in loss of independence with activities of daily living and eventual wheelchair dependence. Initial signs of disease are often overlooked and can lead to mis- or delayed diagnosis. The underlying cause of disease is unknown, and disease progression appears refractory to available treatment options. This review discusses the clinical presentation of inclusion body myositis and the current efforts in diagnosis, and focuses on the current state of research for both nonpharmacological and pharmacological treatment options for this patient group.
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Affiliation(s)
- Lindsay N Alfano
- Nationwide Children's Hospital, Center for Gene Therapy, Columbus, OH, USA
| | - Linda P Lowes
- Nationwide Children's Hospital, Center for Gene Therapy, Columbus, OH, USA
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16
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Auranen M, Palmio J, Ylikallio E, Huovinen S, Paetau A, Sandell S, Haapasalo H, Viitaniemi K, Piirilä P, Tyynismaa H, Udd B. PFKM gene defect and glycogen storage disease GSDVII with misleading enzyme histochemistry. NEUROLOGY-GENETICS 2015; 1:e7. [PMID: 27066546 PMCID: PMC4821086 DOI: 10.1212/nxg.0000000000000007] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/23/2015] [Accepted: 05/11/2015] [Indexed: 11/15/2022]
Abstract
Objective: To elaborate the diagnostic methods used as “gold standard” in one of the most common glycogen storage diseases (GSDs), Tarui disease (GSDVII). Methods: Two siblings with disease suggestive of GSD underwent thorough clinical analysis, including muscle biopsy, muscle MRI, exercise tests, laboratory examinations, and whole-exome sequencing (WES). Results: Both siblings had juvenile-onset exercise intolerance with cramping and infrequent myoglobinuria. Muscle biopsy showed extralysosomal glycogen accumulation, but because of normal phosphofructokinase histochemistry, GSDVII was thought to be excluded. However, WES revealed a causative homozygous PFKM gene defect, R39Q, in both siblings, establishing the diagnosis of GSDVII, which was confirmed by very low residual phosphofructo-1-kinase (PFK) enzyme activity in biochemical studies. Conclusions: We suggest that in patients with suspicion of GSD and extralysosomal glycogen accumulation, biochemical activity assay of PFK followed by molecular genetics should be performed even when enzyme histochemistry is normal.
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Affiliation(s)
- Mari Auranen
- Research Programs Unit (M.A., E.Y., H.T.), Molecular Neurology, Biomedicum Helsinki, University of Helsinki, Helsinki, Finland; Clinical Neurosciences (M.A.), Neurology, University of Helsinki and Helsinki University Hospital, Helsinki, Finland; Neuromuscular Research Center (J.P., S.S., K.V., B.U.), Tampere University Hospital and University of Tampere, Tampere, Finland; Department of Pathology (S.H., H.H.), Fimlab Laboratories, University Hospital and University of Tampere, Tampere, Finland; Department of Pathology (A.P.), HUSLAB, University of Helsinki and Helsinki University Hospital, Helsinki, Finland; Department of Neurology (S.S.), Seinäjoki Central Hospital, Seinäjoki, Finland; and Unit of Clinical Physiology (P.P.), HUS Medical Imaging Center, Helsinki University Hospital, Helsinki, Finland
| | - Johanna Palmio
- Research Programs Unit (M.A., E.Y., H.T.), Molecular Neurology, Biomedicum Helsinki, University of Helsinki, Helsinki, Finland; Clinical Neurosciences (M.A.), Neurology, University of Helsinki and Helsinki University Hospital, Helsinki, Finland; Neuromuscular Research Center (J.P., S.S., K.V., B.U.), Tampere University Hospital and University of Tampere, Tampere, Finland; Department of Pathology (S.H., H.H.), Fimlab Laboratories, University Hospital and University of Tampere, Tampere, Finland; Department of Pathology (A.P.), HUSLAB, University of Helsinki and Helsinki University Hospital, Helsinki, Finland; Department of Neurology (S.S.), Seinäjoki Central Hospital, Seinäjoki, Finland; and Unit of Clinical Physiology (P.P.), HUS Medical Imaging Center, Helsinki University Hospital, Helsinki, Finland
| | - Emil Ylikallio
- Research Programs Unit (M.A., E.Y., H.T.), Molecular Neurology, Biomedicum Helsinki, University of Helsinki, Helsinki, Finland; Clinical Neurosciences (M.A.), Neurology, University of Helsinki and Helsinki University Hospital, Helsinki, Finland; Neuromuscular Research Center (J.P., S.S., K.V., B.U.), Tampere University Hospital and University of Tampere, Tampere, Finland; Department of Pathology (S.H., H.H.), Fimlab Laboratories, University Hospital and University of Tampere, Tampere, Finland; Department of Pathology (A.P.), HUSLAB, University of Helsinki and Helsinki University Hospital, Helsinki, Finland; Department of Neurology (S.S.), Seinäjoki Central Hospital, Seinäjoki, Finland; and Unit of Clinical Physiology (P.P.), HUS Medical Imaging Center, Helsinki University Hospital, Helsinki, Finland
| | - Sanna Huovinen
- Research Programs Unit (M.A., E.Y., H.T.), Molecular Neurology, Biomedicum Helsinki, University of Helsinki, Helsinki, Finland; Clinical Neurosciences (M.A.), Neurology, University of Helsinki and Helsinki University Hospital, Helsinki, Finland; Neuromuscular Research Center (J.P., S.S., K.V., B.U.), Tampere University Hospital and University of Tampere, Tampere, Finland; Department of Pathology (S.H., H.H.), Fimlab Laboratories, University Hospital and University of Tampere, Tampere, Finland; Department of Pathology (A.P.), HUSLAB, University of Helsinki and Helsinki University Hospital, Helsinki, Finland; Department of Neurology (S.S.), Seinäjoki Central Hospital, Seinäjoki, Finland; and Unit of Clinical Physiology (P.P.), HUS Medical Imaging Center, Helsinki University Hospital, Helsinki, Finland
| | - Anders Paetau
- Research Programs Unit (M.A., E.Y., H.T.), Molecular Neurology, Biomedicum Helsinki, University of Helsinki, Helsinki, Finland; Clinical Neurosciences (M.A.), Neurology, University of Helsinki and Helsinki University Hospital, Helsinki, Finland; Neuromuscular Research Center (J.P., S.S., K.V., B.U.), Tampere University Hospital and University of Tampere, Tampere, Finland; Department of Pathology (S.H., H.H.), Fimlab Laboratories, University Hospital and University of Tampere, Tampere, Finland; Department of Pathology (A.P.), HUSLAB, University of Helsinki and Helsinki University Hospital, Helsinki, Finland; Department of Neurology (S.S.), Seinäjoki Central Hospital, Seinäjoki, Finland; and Unit of Clinical Physiology (P.P.), HUS Medical Imaging Center, Helsinki University Hospital, Helsinki, Finland
| | - Satu Sandell
- Research Programs Unit (M.A., E.Y., H.T.), Molecular Neurology, Biomedicum Helsinki, University of Helsinki, Helsinki, Finland; Clinical Neurosciences (M.A.), Neurology, University of Helsinki and Helsinki University Hospital, Helsinki, Finland; Neuromuscular Research Center (J.P., S.S., K.V., B.U.), Tampere University Hospital and University of Tampere, Tampere, Finland; Department of Pathology (S.H., H.H.), Fimlab Laboratories, University Hospital and University of Tampere, Tampere, Finland; Department of Pathology (A.P.), HUSLAB, University of Helsinki and Helsinki University Hospital, Helsinki, Finland; Department of Neurology (S.S.), Seinäjoki Central Hospital, Seinäjoki, Finland; and Unit of Clinical Physiology (P.P.), HUS Medical Imaging Center, Helsinki University Hospital, Helsinki, Finland
| | - Hannu Haapasalo
- Research Programs Unit (M.A., E.Y., H.T.), Molecular Neurology, Biomedicum Helsinki, University of Helsinki, Helsinki, Finland; Clinical Neurosciences (M.A.), Neurology, University of Helsinki and Helsinki University Hospital, Helsinki, Finland; Neuromuscular Research Center (J.P., S.S., K.V., B.U.), Tampere University Hospital and University of Tampere, Tampere, Finland; Department of Pathology (S.H., H.H.), Fimlab Laboratories, University Hospital and University of Tampere, Tampere, Finland; Department of Pathology (A.P.), HUSLAB, University of Helsinki and Helsinki University Hospital, Helsinki, Finland; Department of Neurology (S.S.), Seinäjoki Central Hospital, Seinäjoki, Finland; and Unit of Clinical Physiology (P.P.), HUS Medical Imaging Center, Helsinki University Hospital, Helsinki, Finland
| | - Kati Viitaniemi
- Research Programs Unit (M.A., E.Y., H.T.), Molecular Neurology, Biomedicum Helsinki, University of Helsinki, Helsinki, Finland; Clinical Neurosciences (M.A.), Neurology, University of Helsinki and Helsinki University Hospital, Helsinki, Finland; Neuromuscular Research Center (J.P., S.S., K.V., B.U.), Tampere University Hospital and University of Tampere, Tampere, Finland; Department of Pathology (S.H., H.H.), Fimlab Laboratories, University Hospital and University of Tampere, Tampere, Finland; Department of Pathology (A.P.), HUSLAB, University of Helsinki and Helsinki University Hospital, Helsinki, Finland; Department of Neurology (S.S.), Seinäjoki Central Hospital, Seinäjoki, Finland; and Unit of Clinical Physiology (P.P.), HUS Medical Imaging Center, Helsinki University Hospital, Helsinki, Finland
| | - Päivi Piirilä
- Research Programs Unit (M.A., E.Y., H.T.), Molecular Neurology, Biomedicum Helsinki, University of Helsinki, Helsinki, Finland; Clinical Neurosciences (M.A.), Neurology, University of Helsinki and Helsinki University Hospital, Helsinki, Finland; Neuromuscular Research Center (J.P., S.S., K.V., B.U.), Tampere University Hospital and University of Tampere, Tampere, Finland; Department of Pathology (S.H., H.H.), Fimlab Laboratories, University Hospital and University of Tampere, Tampere, Finland; Department of Pathology (A.P.), HUSLAB, University of Helsinki and Helsinki University Hospital, Helsinki, Finland; Department of Neurology (S.S.), Seinäjoki Central Hospital, Seinäjoki, Finland; and Unit of Clinical Physiology (P.P.), HUS Medical Imaging Center, Helsinki University Hospital, Helsinki, Finland
| | - Henna Tyynismaa
- Research Programs Unit (M.A., E.Y., H.T.), Molecular Neurology, Biomedicum Helsinki, University of Helsinki, Helsinki, Finland; Clinical Neurosciences (M.A.), Neurology, University of Helsinki and Helsinki University Hospital, Helsinki, Finland; Neuromuscular Research Center (J.P., S.S., K.V., B.U.), Tampere University Hospital and University of Tampere, Tampere, Finland; Department of Pathology (S.H., H.H.), Fimlab Laboratories, University Hospital and University of Tampere, Tampere, Finland; Department of Pathology (A.P.), HUSLAB, University of Helsinki and Helsinki University Hospital, Helsinki, Finland; Department of Neurology (S.S.), Seinäjoki Central Hospital, Seinäjoki, Finland; and Unit of Clinical Physiology (P.P.), HUS Medical Imaging Center, Helsinki University Hospital, Helsinki, Finland
| | - Bjarne Udd
- Research Programs Unit (M.A., E.Y., H.T.), Molecular Neurology, Biomedicum Helsinki, University of Helsinki, Helsinki, Finland; Clinical Neurosciences (M.A.), Neurology, University of Helsinki and Helsinki University Hospital, Helsinki, Finland; Neuromuscular Research Center (J.P., S.S., K.V., B.U.), Tampere University Hospital and University of Tampere, Tampere, Finland; Department of Pathology (S.H., H.H.), Fimlab Laboratories, University Hospital and University of Tampere, Tampere, Finland; Department of Pathology (A.P.), HUSLAB, University of Helsinki and Helsinki University Hospital, Helsinki, Finland; Department of Neurology (S.S.), Seinäjoki Central Hospital, Seinäjoki, Finland; and Unit of Clinical Physiology (P.P.), HUS Medical Imaging Center, Helsinki University Hospital, Helsinki, Finland
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17
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Abstract
PURPOSE OF THE REVIEW To describe new insights and developments in the pathogenesis, diagnosis and treatment of sporadic inclusion body myositis (IBM). RECENT FINDINGS Various hypothesis about the pathogenesis of IBM continue to be investigated, including autoimmune factors, mitochondrial dysfunction, protein dyshomeostasis, altered nucleic acid metabolism, myonuclear degeneration and the role of the myostatin pathway. Serum autoantibodies against cytosolic 5'-nucleotidase 1A have been identified in IBM showing moderate diagnostic performance. The differential diagnostic value of histopathological features, including different protein aggregates, continues to be evaluated. MRI may also be of monitoring value in IBM. New therapeutic strategies are being tested in IBM patients, namely the upregulation of the heat shock response and the antagonism of myostatin. SUMMARY Recent important advances have occurred in IBM. These advances, including recent and ongoing clinical trials, may lead to earlier diagnosis and improved understanding and treatment of the disease. Despite improved knowledge, IBM continues to be a puzzling disease and the pathogenesis remains to be clarified. An interdisciplinary, bench to bedside translational research approach is crucial for the successful identification of novel treatments for this debilitating, currently untreatable disorder.
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18
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Murnyák B, Bodoki L, Vincze M, Griger Z, Csonka T, Szepesi R, Kurucz A, Dankó K, Hortobágyi T. Inclusion body myositis - pathomechanism and lessons from genetics. Open Med (Wars) 2015; 10:188-193. [PMID: 28352694 PMCID: PMC5152972 DOI: 10.1515/med-2015-0030] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2014] [Accepted: 01/30/2015] [Indexed: 11/26/2022] Open
Abstract
Inclusion body myositis is a rare, late-onset myopathy. Both inflammatory and myodegenerative features play an important role in their pathogenesis. Overlapping clinicopathological entities are the familial inclusion body myopathies with or without dementia. These myopathies share several clinical and pathological features with the sporadic inflammatory disease. Therefore, better understanding of the genetic basis and pathomechanism of these rare familial cases may advance our knowledge and enable more effective treatment options in sporadic IBM, which is currently considered a relentlessly progressive incurable disease.
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Affiliation(s)
| | - Levente Bodoki
- Institute of Internal Medicine, Third Department of Internal Medicine, Division of Clinical Immunology
| | - Melinda Vincze
- Institute of Internal Medicine, Third Department of Internal Medicine, Division of Clinical Immunology
| | - Zoltán Griger
- Institute of Internal Medicine, Third Department of Internal Medicine, Division of Clinical Immunology
| | - Tamás Csonka
- Division of Neuropathology, Institute of Pathology
| | - Rita Szepesi
- Department of Neurology, University of Debrecen, Faculty of Medicine, Debrecen, Hungary
| | | | - Katalin Dankó
- Institute of Internal Medicine, Third Department of Internal Medicine, Division of Clinical Immunology
| | - Tibor Hortobágyi
- University of Debrecen, Faculty of Medicine, Institute of Pathology, Division of Neuropathology, 4032 Debrecen, Nagyerdei krt. 98. Tel.: + 36 52 255-248
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19
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Herbert MK, Stammen-Vogelzangs J, Verbeek MM, Rietveld A, Lundberg IE, Chinoy H, Lamb JA, Cooper RG, Roberts M, Badrising UA, De Bleecker JL, Machado PM, Hanna MG, Plestilova L, Vencovsky J, van Engelen BG, Pruijn GJM. Disease specificity of autoantibodies to cytosolic 5'-nucleotidase 1A in sporadic inclusion body myositis versus known autoimmune diseases. Ann Rheum Dis 2015; 75:696-701. [PMID: 25714931 DOI: 10.1136/annrheumdis-2014-206691] [Citation(s) in RCA: 95] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2014] [Accepted: 02/08/2015] [Indexed: 02/04/2023]
Abstract
OBJECTIVES The diagnosis of inclusion body myositis (IBM) can be challenging as it can be difficult to clinically distinguish from other forms of myositis, particularly polymyositis (PM). Recent studies have shown frequent presence of autoantibodies directed against cytosolic 5'-nucleotidase 1A (cN-1A) in patients with IBM. We therefore, examined the autoantigenicity and disease specificity of major epitopes of cN-1A in patients with sporadic IBM compared with healthy and disease controls. METHODS Serum samples obtained from patients with IBM (n=238), PM and dermatomyositis (DM) (n=185), other autoimmune diseases (n=246), other neuromuscular diseases (n=93) and healthy controls (n=35) were analysed for the presence of autoantibodies using immunodominant cN-1A peptide ELISAs. RESULTS Autoantibodies directed against major epitopes of cN-1A were frequent in patients with IBM (37%) but not in PM, DM or non-autoimmune neuromuscular diseases (<5%). Anti-cN-1A reactivity was also observed in some other autoimmune diseases, particularly Sjögren's syndrome (SjS; 36%) and systemic lupus erythematosus (SLE; 20%). CONCLUSIONS In summary, we found frequent anti-cN-1A autoantibodies in sera from patients with IBM. Heterogeneity in reactivity with the three immunodominant epitopes indicates that serological assays should not be limited to a distinct epitope region. The similar reactivities observed for SjS and SLE demonstrate the need to further investigate whether distinct IBM-specific epitopes exist.
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Affiliation(s)
- Megan K Herbert
- Department of Biomolecular Chemistry, Radboud Institute for Molecular Life Sciences and Institute for Molecules and Materials, Radboud University, Nijmegen, The Netherlands
| | - Judith Stammen-Vogelzangs
- Department of Biomolecular Chemistry, Radboud Institute for Molecular Life Sciences and Institute for Molecules and Materials, Radboud University, Nijmegen, The Netherlands
| | - Marcel M Verbeek
- Department of Neurology, Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Centre, Nijmegen, The Netherlands Department of Laboratory Medicine, Radboud University Medical Centre, Nijmegen, The Netherlands
| | - Anke Rietveld
- Department of Neurology, Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Centre, Nijmegen, The Netherlands
| | - Ingrid E Lundberg
- Rheumatology Unit, Department of Medicine, Karolinska Institutet/Karolinska University Hospital, Stockholm, Sweden
| | - Hector Chinoy
- Centre for Musculoskeletal Research, Manchester Academic Health Science Centre, The University of Manchester, Manchester, UK
| | - Janine A Lamb
- Centre for Integrated Genomic Medical Research, The University of Manchester, Manchester, UK
| | - Robert G Cooper
- Faculty of Health & Life Sciences, MRC/ARUK Institute of Ageing and Chronic Disease, University of Liverpool, Liverpool, UK
| | - Mark Roberts
- Salford Royal NHS Foundation Trust, Manchester, UK
| | - Umesh A Badrising
- Department of Neurology, Leiden University Medical Centre, Leiden, The Netherlands
| | - Jan L De Bleecker
- Department of Neurology, Neuromuscular Reference Centre, Ghent University Hospital, Ghent, Belgium
| | - Pedro M Machado
- MRC Centre for Neuromuscular Diseases, University College London, London, UK
| | - Michael G Hanna
- MRC Centre for Neuromuscular Diseases, University College London, London, UK
| | - Lenka Plestilova
- Department of Rheumatology, First Faculty of Medicine, Institute of Rheumatology, Charles University, Prague, Czech Republic
| | - Jiri Vencovsky
- Department of Rheumatology, First Faculty of Medicine, Institute of Rheumatology, Charles University, Prague, Czech Republic
| | - Baziel G van Engelen
- Department of Neurology, Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Centre, Nijmegen, The Netherlands
| | - Ger J M Pruijn
- Department of Biomolecular Chemistry, Radboud Institute for Molecular Life Sciences and Institute for Molecules and Materials, Radboud University, Nijmegen, The Netherlands
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20
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Homma S, Beermann ML, Boyce FM, Miller JB. Expression of FSHD-related DUX4-FL alters proteostasis and induces TDP-43 aggregation. Ann Clin Transl Neurol 2015; 2:151-66. [PMID: 25750920 PMCID: PMC4338956 DOI: 10.1002/acn3.158] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2014] [Revised: 11/17/2014] [Accepted: 11/18/2014] [Indexed: 11/17/2022] Open
Abstract
Objective Pathogenesis in facioscapulohumeral muscular dystrophy (FSHD) appears to be due to aberrant expression, particularly in skeletal muscle nuclei, of the full-length isoform of DUX4 (DUX4-FL). Expression of DUX4-FL is known to alter gene expression and to be cytotoxic, but cell responses to DUX4-FL are not fully understood. Our study was designed to identify cellular mechanisms of pathogenesis caused by DUX4-FL expression. Methods We used human myogenic cell cultures to analyze the effects of DUX4-FL when it was expressed either from its endogenous promoter in FSHD cells or by exogenous expression using BacMam vectors. We focused on determining the effects of DUX4-FL on protein ubiquitination and turnover and on aggregation of TDP-43. Results Human FSHD myotubes with endogenous DUX4-FL expression showed both altered nuclear and cytoplasmic distributions of ubiquitinated proteins and aggregation of TDP-43 in DUX4-FL-expressing nuclei. Similar changes were found upon exogenous expression of DUX4-FL, but were not seen upon expression of the non-toxic short isoform DUX4-S. DUX4-FL expression also inhibited protein turnover in a model system and increased the amounts of insoluble ubiquitinated proteins and insoluble TDP-43. Finally, inhibition of the ubiquitin–proteasome system with MG132 produced TDP-43 aggregation similar to DUX4-FL expression. Interpretations Our results identify DUX4-FL-induced inhibition of protein turnover and aggregation of TDP-43, which are pathological changes also found in diseases such as amyotrophic lateral sclerosis and inclusion body myopathy, as potential pathological mechanisms in FSHD.
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Affiliation(s)
- Sachiko Homma
- Neuromuscular Biology & Disease Group, Departments of Neurology and Physiology & Biophysics, Boston University School of Medicine Boston, Massachusetts, 02118
| | - Mary Lou Beermann
- Neuromuscular Biology & Disease Group, Departments of Neurology and Physiology & Biophysics, Boston University School of Medicine Boston, Massachusetts, 02118
| | - Frederick M Boyce
- Department of Neurology, Massachusetts General Hospital Boston, Massachusetts, 02114
| | - Jeffrey Boone Miller
- Neuromuscular Biology & Disease Group, Departments of Neurology and Physiology & Biophysics, Boston University School of Medicine Boston, Massachusetts, 02118
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21
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Weihl CC, Baloh RH, Lee Y, Chou TF, Pittman SK, Lopate G, Allred P, Jockel-Balsarotti J, Pestronk A, Harms MB. Targeted sequencing and identification of genetic variants in sporadic inclusion body myositis. Neuromuscul Disord 2015; 25:289-96. [PMID: 25617006 DOI: 10.1016/j.nmd.2014.12.009] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2014] [Revised: 12/15/2014] [Accepted: 12/28/2014] [Indexed: 12/14/2022]
Abstract
Sporadic inclusion body myositis (sIBM) has clinical, pathologic and pathomechanistic overlap with some inherited muscle and neurodegenerative disorders. In this study, DNA from 79 patients with sIBM was collected and the sequencing of 38 genes associated with hereditary inclusion body myopathy (IBM), myofibrillar myopathy, Emery-Dreifuss muscular dystrophy, distal myopathy, amyotrophic lateral sclerosis and dementia along with C9orf72 hexanucleotide repeat analysis was performed. No C9orf72 repeat expansions were identified, but; 27 rare (minor allele frequency <1%) missense coding variants in several other genes were identified. One patient carried a p.R95C missense mutation in VCP and another carried a previously reported p.I27V missense mutation in VCP. Mutations in VCP cause IBM associated with Paget's disease of the bone (PDB) and fronto-temporal dementia (IBMPFD). Neither patient had a family history of weakness or manifested other symptoms reported with VCP mutations such as PDB or dementia. In vitro analysis of these VCP variants found that they both disrupted autophagy similar to other pathogenic mutations. Although no clear genetic etiology has been implicated in sIBM pathogenesis, our study suggests that genetic evaluation in sIBM may be clinically meaningful and lend insight into its pathomechanism.
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Affiliation(s)
- Conrad C Weihl
- Department of Neurology, Hope Center for Neurologic Disorders, Washington University School of Medicine, Saint Louis, MO 63110, United States.
| | - Robert H Baloh
- Department of Neurology, Regenerative Medicine Institute, Cedars-Sinai Medical Center, 8730 Alden Drive, Los Angeles, CA 90048, United States
| | - Youjin Lee
- Department of Neurology, Hope Center for Neurologic Disorders, Washington University School of Medicine, Saint Louis, MO 63110, United States
| | - Tsui-Fen Chou
- Division of Medical Genetics, Department of Pediatrics, Harbor-UCLA Medical Centre, Los Angeles Biomedical Research Institute, Torrance, CA 90502, United States
| | - Sara K Pittman
- Department of Neurology, Hope Center for Neurologic Disorders, Washington University School of Medicine, Saint Louis, MO 63110, United States
| | - Glenn Lopate
- Department of Neurology, Hope Center for Neurologic Disorders, Washington University School of Medicine, Saint Louis, MO 63110, United States
| | - Peggy Allred
- Department of Neurology, Regenerative Medicine Institute, Cedars-Sinai Medical Center, 8730 Alden Drive, Los Angeles, CA 90048, United States
| | - Jennifer Jockel-Balsarotti
- Department of Neurology, Hope Center for Neurologic Disorders, Washington University School of Medicine, Saint Louis, MO 63110, United States
| | - Alan Pestronk
- Department of Neurology, Hope Center for Neurologic Disorders, Washington University School of Medicine, Saint Louis, MO 63110, United States
| | - Matthew B Harms
- Department of Neurology, Hope Center for Neurologic Disorders, Washington University School of Medicine, Saint Louis, MO 63110, United States
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Machado PM, Ahmed M, Brady S, Gang Q, Healy E, Morrow JM, Wallace AC, Dewar L, Ramdharry G, Parton M, Holton JL, Houlden H, Greensmith L, Hanna MG. Ongoing developments in sporadic inclusion body myositis. Curr Rheumatol Rep 2014; 16:477. [PMID: 25399751 PMCID: PMC4233319 DOI: 10.1007/s11926-014-0477-9] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Sporadic inclusion body myositis (IBM) is an acquired muscle disorder associated with ageing, for which there is no effective treatment. Ongoing developments include: genetic studies that may provide insights regarding the pathogenesis of IBM, improved histopathological markers, the description of a new IBM autoantibody, scrutiny of the diagnostic utility of clinical features and biomarkers, the refinement of diagnostic criteria, the emerging use of MRI as a diagnostic and monitoring tool, and new pathogenic insights that have led to novel therapeutic approaches being trialled for IBM, including treatments with the objective of restoring protein homeostasis and myostatin blockers. The effect of exercise in IBM continues to be investigated. However, despite these ongoing developments, the aetiopathogenesis of IBM remains uncertain. A translational and multidisciplinary collaborative approach is critical to improve the diagnosis, treatment, and care of patients with IBM.
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Affiliation(s)
- Pedro M. Machado
- MRC Centre for Neuromuscular Diseases, Institute of Neurology, University College London, Box 102, 8-11 Queen Square, London, WC1N 3BG UK
| | - Mhoriam Ahmed
- MRC Centre for Neuromuscular Diseases, Institute of Neurology, University College London, Box 102, 8-11 Queen Square, London, WC1N 3BG UK
- Sobell Department of Motor Neuroscience and Movement Disorders, Institute of Neurology, University College London, Queen Square, London, WC1N 3BG UK
| | - Stefen Brady
- MRC Centre for Neuromuscular Diseases, Institute of Neurology, University College London, Box 102, 8-11 Queen Square, London, WC1N 3BG UK
| | - Qiang Gang
- MRC Centre for Neuromuscular Diseases, Institute of Neurology, University College London, Box 102, 8-11 Queen Square, London, WC1N 3BG UK
| | - Estelle Healy
- MRC Centre for Neuromuscular Diseases, Institute of Neurology, University College London, Box 102, 8-11 Queen Square, London, WC1N 3BG UK
| | - Jasper M. Morrow
- MRC Centre for Neuromuscular Diseases, Institute of Neurology, University College London, Box 102, 8-11 Queen Square, London, WC1N 3BG UK
| | - Amanda C. Wallace
- MRC Centre for Neuromuscular Diseases, Institute of Neurology, University College London, Box 102, 8-11 Queen Square, London, WC1N 3BG UK
| | - Liz Dewar
- MRC Centre for Neuromuscular Diseases, Institute of Neurology, University College London, Box 102, 8-11 Queen Square, London, WC1N 3BG UK
| | - Gita Ramdharry
- MRC Centre for Neuromuscular Diseases, Institute of Neurology, University College London, Box 102, 8-11 Queen Square, London, WC1N 3BG UK
| | - Matthew Parton
- MRC Centre for Neuromuscular Diseases, Institute of Neurology, University College London, Box 102, 8-11 Queen Square, London, WC1N 3BG UK
| | - Janice L. Holton
- MRC Centre for Neuromuscular Diseases, Institute of Neurology, University College London, Box 102, 8-11 Queen Square, London, WC1N 3BG UK
| | - Henry Houlden
- MRC Centre for Neuromuscular Diseases, Institute of Neurology, University College London, Box 102, 8-11 Queen Square, London, WC1N 3BG UK
| | - Linda Greensmith
- MRC Centre for Neuromuscular Diseases, Institute of Neurology, University College London, Box 102, 8-11 Queen Square, London, WC1N 3BG UK
- Sobell Department of Motor Neuroscience and Movement Disorders, Institute of Neurology, University College London, Queen Square, London, WC1N 3BG UK
| | - Michael G. Hanna
- MRC Centre for Neuromuscular Diseases, Institute of Neurology, University College London, Box 102, 8-11 Queen Square, London, WC1N 3BG UK
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Kitajima Y, Tashiro Y, Suzuki N, Warita H, Kato M, Tateyama M, Ando R, Izumi R, Yamazaki M, Abe M, Sakimura K, Ito H, Urushitani M, Nagatomi R, Takahashi R, Aoki M. Proteasome dysfunction induces muscle growth defects and protein aggregation. J Cell Sci 2014; 127:5204-17. [PMID: 25380823 PMCID: PMC4265737 DOI: 10.1242/jcs.150961] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
The ubiquitin–proteasome and autophagy–lysosome pathways are the two major routes of protein and organelle clearance. The role of the proteasome pathway in mammalian muscle has not been examined in vivo. In this study, we report that the muscle-specific deletion of a crucial proteasomal gene, Rpt3 (also known as Psmc4), resulted in profound muscle growth defects and a decrease in force production in mice. Specifically, developing muscles in conditional Rpt3-knockout animals showed dysregulated proteasomal activity. The autophagy pathway was upregulated, but the process of autophagosome formation was impaired. A microscopic analysis revealed the accumulation of basophilic inclusions and disorganization of the sarcomeres in young adult mice. Our results suggest that appropriate proteasomal activity is important for muscle growth and for maintaining myofiber integrity in collaboration with autophagy pathways. The deletion of a component of the proteasome complex contributed to myofiber degeneration and weakness in muscle disorders that are characterized by the accumulation of abnormal inclusions.
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Affiliation(s)
- Yasuo Kitajima
- Department of Neurology, Tohoku University School of Medicine, 1-1 Seiryo-machi, Aoba-ku, Sendai 980-8574, Japan Department of Medicine and Science in Sports and Exercise, Tohoku University Graduate School of Medicine, 1-1 Seiryo-machi, Aoba-ku, Sendai 980-8574, Japan
| | - Yoshitaka Tashiro
- Department of Neurology, Kyoto University Graduate School of Medicine, Kyoto 606-8501, Japan
| | - Naoki Suzuki
- Department of Neurology, Tohoku University School of Medicine, 1-1 Seiryo-machi, Aoba-ku, Sendai 980-8574, Japan
| | - Hitoshi Warita
- Department of Neurology, Tohoku University School of Medicine, 1-1 Seiryo-machi, Aoba-ku, Sendai 980-8574, Japan
| | - Masaaki Kato
- Department of Neurology, Tohoku University School of Medicine, 1-1 Seiryo-machi, Aoba-ku, Sendai 980-8574, Japan
| | - Maki Tateyama
- Department of Neurology, Tohoku University School of Medicine, 1-1 Seiryo-machi, Aoba-ku, Sendai 980-8574, Japan
| | - Risa Ando
- Department of Neurology, Tohoku University School of Medicine, 1-1 Seiryo-machi, Aoba-ku, Sendai 980-8574, Japan
| | - Rumiko Izumi
- Department of Neurology, Tohoku University School of Medicine, 1-1 Seiryo-machi, Aoba-ku, Sendai 980-8574, Japan
| | - Maya Yamazaki
- Niigata University, Department of Cellular Neurobiology Brain Research Institute, Niigata 951-8510, Japan
| | - Manabu Abe
- Niigata University, Department of Cellular Neurobiology Brain Research Institute, Niigata 951-8510, Japan
| | - Kenji Sakimura
- Niigata University, Department of Cellular Neurobiology Brain Research Institute, Niigata 951-8510, Japan
| | - Hidefumi Ito
- Department of Neurology, Wakayama Medical University Graduate School of Medicine, Wakayama 641-8510, Japan
| | - Makoto Urushitani
- Department of Neurology, Kyoto University Graduate School of Medicine, Kyoto 606-8501, Japan
| | - Ryoichi Nagatomi
- Department of Medicine and Science in Sports and Exercise, Tohoku University Graduate School of Medicine, 1-1 Seiryo-machi, Aoba-ku, Sendai 980-8574, Japan
| | - Ryosuke Takahashi
- Department of Neurology, Kyoto University Graduate School of Medicine, Kyoto 606-8501, Japan
| | - Masashi Aoki
- Department of Neurology, Tohoku University School of Medicine, 1-1 Seiryo-machi, Aoba-ku, Sendai 980-8574, Japan
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Abstract
AbstractBackgroundStatins have recently been reported to cause a rare autoimmune inflammatory and/or necrotic myopathy that begins or persists after drug cessation.MethodsWe report on 26 patients seen at a neuromuscular centre between 2005 and 2011 who demonstrated muscle weakness/myalgias and creatine kinase elevations during or after statin treatment with continuation of signs and symptoms despite statin withdrawal.ResultsAll patients were treated with immunosuppressive therapy with good response; all improved biochemically and 86% improved clinically. Sixty-five percent of patients who attempted to taper off immunosuppressive therapy relapsed. We report on a novel finding whereby five of the seven patients who underwent multiple biopsies throughout their disease demonstrated a transformation of their histological diagnosis, with four progressing from having myofibre necrosis with minimal or no inflammation to a diagnosis of polymyositis.ConclusionsThis study offers preliminary evidence that statin-associated necrotizing myopathy and statin-associated polymyositis may not be separate entities but are part of the same pathophysiological spectrum. Both entities respond well to immunosuppression.
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Gene expression profiling in tibial muscular dystrophy reveals unfolded protein response and altered autophagy. PLoS One 2014; 9:e90819. [PMID: 24618559 PMCID: PMC3949689 DOI: 10.1371/journal.pone.0090819] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2013] [Accepted: 02/04/2014] [Indexed: 11/19/2022] Open
Abstract
Tibial muscular dystrophy (TMD) is a late onset, autosomal dominant distal myopathy that results from mutations in the two last domains of titin. The cascade of molecular events leading from the causative Titin mutations to the preterm death of muscle cells in TMD is largely unknown. In this study we examined the mRNA and protein changes associated with the myopathology of TMD. To identify these components we performed gene expression profiling using muscle biopsies from TMD patients and healthy controls. The profiling results were confirmed through quantitative real-time PCR and protein level analysis. One of the pathways identified was activation of endoplasmic reticulum (ER) stress response. ER stress activates the unfolded protein response (UPR) pathway. UPR activation was supported by elevation of the marker genes HSPA5, ERN1 and the UPR specific XBP1 splice form. However, UPR activation appears to be insufficient to correct the protein abnormalities causing its activation because degenerative TMD muscle fibres show an increase in ubiquitinated protein inclusions. Abnormalities of VCP-associated degradation pathways are also suggested by the presence of proteolytic VCP fragments in western blotting, and VCP's accumulation within rimmed vacuoles in TMD muscle fibres together with p62 and LC3B positive autophagosomes. Thus, pathways controlling turnover and degradation, including autophagy, are distorted and lead to degeneration and loss of muscle fibres.
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Stübgen JP. A review on the association between inflammatory myopathies and vaccination. Autoimmun Rev 2014; 13:31-9. [DOI: 10.1016/j.autrev.2013.08.005] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2013] [Accepted: 08/16/2013] [Indexed: 11/16/2022]
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Abstract
PURPOSE OF REVIEW The purpose of this study is to review recent scientific advances relating to the natural history, cause, treatment and serum and imaging biomarkers of inclusion body myositis (IBM). RECENT FINDINGS Several theories regarding the aetiopathogenesis of IBM are being explored and new therapeutic approaches are being investigated. New diagnostic criteria have been proposed, reflecting the knowledge that the diagnostic pathological findings may be absent in patients with clinically typical IBM. The role of MRI in IBM is expanding and knowledge about pathological biomarkers is increasing. The recent description of autoantibodies to cytosolic 5' nucleotidase 1A in patients with IBM is a potentially important advance that may aid early diagnosis and provides new evidence regarding the role of autoimmunity in IBM. SUMMARY IBM remains an enigmatic and often misdiagnosed disease. The pathogenesis of the disease is still not fully understood. To date, pharmacological treatment trials have failed to show clear efficacy. Future research should continue to focus on improving understanding of the pathophysiological mechanisms of the disease and on the identification of reliable and sensitive outcome measures for clinical trials. IBM is a rare disease and international multicentre collaboration for trials is important to translate research advances into improved patient outcomes.
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Affiliation(s)
- Pedro Machado
- MRC Centre for Neuromuscular Diseases, Institute of Neurology, University College London, London, UK *Pedro Machado and Stefen Brady have contributed equally to this article
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Hiniker A, Daniels BH, Lee HS, Margeta M. Comparative utility of LC3, p62 and TDP-43 immunohistochemistry in differentiation of inclusion body myositis from polymyositis and related inflammatory myopathies. Acta Neuropathol Commun 2013; 1:29. [PMID: 24252466 PMCID: PMC3893502 DOI: 10.1186/2051-5960-1-29] [Citation(s) in RCA: 58] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2013] [Accepted: 06/18/2013] [Indexed: 11/29/2022] Open
Abstract
Background Inclusion body myositis (IBM) is a slowly progressive inflammatory myopathy of the elderly that does not show significant clinical improvement in response to steroid therapy. Distinguishing IBM from polymyositis (PM) is clinically important since PM is steroid-responsive; however, the two conditions can show substantial histologic overlap. Results We performed quantitative immunohistochemistry for (1) autophagic markers LC3 and p62 and (2) protein aggregation marker TDP-43 in 53 subjects with pathologically diagnosed PM, IBM, and two intermediate T cell-mediated inflammatory myopathies (polymyositis with COX-negative fibers and possible IBM). The percentage of stained fibers was significantly higher in IBM than PM for all three immunostains, but the markers varied in sensitivity and specificity. In particular, both LC3 and p62 were sensitive markers of IBM, but the tradeoff between sensitivity and specificity was smaller (and diagnostic utility thus greater) for LC3 than for p62. In contrast, TDP-43 immunopositivity was highly specific for IBM, but the sensitivity of this test was low, with definitive staining present in just 67% of IBM cases. Conclusions To differentiate IBM from PM, we thus recommend using a panel of LC3 and TDP-43 antibodies: the finding of <14% LC3-positive fibers helps exclude IBM, while >7% of TDP-43-positive fibers strongly supports a diagnosis of IBM. These data provide support for the hypothesis that disruption of autophagy and protein aggregation contribute to IBM pathogenesis.
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Yamashita S, Kimura E, Tawara N, Sakaguchi H, Nakama T, Maeda Y, Hirano T, Uchino M, Ando Y. Optineurin is potentially associated with TDP-43 and involved in the pathogenesis of inclusion body myositis. Neuropathol Appl Neurobiol 2013; 39:406-16. [DOI: 10.1111/j.1365-2990.2012.01297.x] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Pluk H, van Hoeve BJA, van Dooren SHJ, Stammen-Vogelzangs J, van der Heijden A, Schelhaas HJ, Verbeek MM, Badrising UA, Arnardottir S, Gheorghe K, Lundberg IE, Boelens WC, van Engelen BG, Pruijn GJM. Autoantibodies to cytosolic 5'-nucleotidase 1A in inclusion body myositis. Ann Neurol 2013; 73:397-407. [PMID: 23460448 DOI: 10.1002/ana.23822] [Citation(s) in RCA: 177] [Impact Index Per Article: 16.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2012] [Revised: 11/20/2012] [Accepted: 11/21/2012] [Indexed: 11/05/2022]
Abstract
OBJECTIVE Sporadic inclusion body myositis (sIBM) is an inflammatory myopathy characterized by both degenerative and autoimmune features. In contrast to other inflammatory myopathies, myositis-specific autoantibodies had not been found in sIBM patients until recently. We used human skeletal muscle extracts as a source of antigens to detect autoantibodies in sIBM and to characterize the corresponding antigen. METHODS Autoantibodies to skeletal muscle antigens were detected by immunoblotting. The target antigen was immunoaffinity-purified from skeletal muscle extracts and characterized by mass spectrometry. A cDNA encoding this protein was cloned and expressed in vitro, and its recognition by patient sera was analyzed in an immunoprecipitation assay. Epitopes were mapped using microarrays of overlapping peptides. RESULTS An Mr 44,000 polypeptide (Mup44) was frequently targeted by sIBM autoantibodies. The target protein was purified, and subsequent mass spectrometry analysis revealed that Mup44 is the cytosolic 5'-nucleotidase 1A (cN1A). By immunoprecipitation of recombinant cN1A, high concentrations of anti-Mup44 autoantibodies were detected in 33% of sIBM patient sera, whereas their prevalence in dermatomyositis, polymyositis, and other neuromuscular disorders appeared to be rare (4.2%, 4.5%, and 3.2%, respectively). Low concentrations of anti-Mup44 antibodies were found in myositis as well as other neuromuscular disorders, but not in healthy controls. Three major autoepitope regions of cN1A were mapped by using microarrays containing a set of overlapping peptides covering the complete cN1A amino acid sequence. INTERPRETATION Anti-Mup44 autoantibodies, which are targeted to cN1A, represent the first serological biomarker for sIBM and may facilitate the diagnosis of this type of myositis.
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Affiliation(s)
- Helma Pluk
- Department of Biomolecular Chemistry, Institute for Molecules and Materials and Nijmegen Center for Molecular Life Sciences, Radboud University Nijmegen, Nijmegen, the Netherlands
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Lee HK, Rocnik E, Fu Q, Kwon B, Zeng L, Walsh K, Querfurth H. Foxo/atrogin induction in human and experimental myositis. Neurobiol Dis 2013; 46:463-75. [PMID: 22590725 DOI: 10.1016/j.nbd.2012.02.011] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Skeletal muscle atrophy can occur rapidly in various fasting, cancerous, systemic inflammatory, deranged metabolic or neurogenic states. The ubiquitin ligase Atrogin-1 (MAFbx) is induced in animal models of these conditions, causing excessive myoprotein degradation. It is unknown if Atrogin upregulation also occurs in acquired human myositis. Intracellular β-amyloid (Aβi), phosphorylated neurofilaments, scattered infiltrates and atrophy involving selective muscle groups characterize human sporadic Inclusion Body Myositis (sIBM). In Polymyositis (PM), inflammation is more pronounced and atrophy is symmetric and proximal. IBM and PM share various inflammatory markers. We found that forkhead family transcription factor Foxo3A is directed to the nucleus and Atrogin-1 transcript is increased in both conditions. Expression of Aβ in transgenic mice and differentiated C2C12 myotubes was sufficient to upregulate Atrogin-1 mRNA and cause atrophy. Aβi reduces levels of p-Akt and downstream p-Foxo3A, resulting in Foxo3A translocation and Atrogin-1 induction. In a mouse model of autoimmune myositis, cellular inflammation alone was associated with similar Foxo3A and Atrogin changes. Thus, either Aβi accumulation or cellular immune stimulation may independently drive muscle atrophy in sIBM and PM, respectively, through pathways converging on Foxo and Atrogin-1. In sIBM it is additionally possible that both mechanisms synergize.
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Affiliation(s)
- Han-Kyu Lee
- Department of Neurology, Rhode Island Hospital, 593 Eddy Street, Providence, RI 02903, USA
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Ernste FC, Reed AM. Idiopathic inflammatory myopathies: current trends in pathogenesis, clinical features, and up-to-date treatment recommendations. Mayo Clin Proc 2013; 88:83-105. [PMID: 23274022 DOI: 10.1016/j.mayocp.2012.10.017] [Citation(s) in RCA: 112] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/16/2012] [Revised: 10/30/2012] [Accepted: 10/31/2012] [Indexed: 01/13/2023]
Abstract
Recently, there have been important advances in the understanding of the pathophysiologic features, assessment, and management of patients with a newly diagnosed idiopathic inflammatory myopathy (IIM). Myositis-specific autoantibodies have been identified to define patient subgroups and offer prognostic implications. Similarly, proinflammatory cytokines, such as interleukin 6 and type 1 interferon-dependent genes, may serve as potential biomarkers of disease activity in adult and juvenile patients with dermatomyositis (DM). Moreover, magnetic resonance imaging has become an important modality for the assessment of muscle inflammation in adult IIM and juvenile DM. Immune-mediated necrotizing myopathies also are being recognized as a subset of IIM triggered by medications such as statins. However, confusion exists regarding effective management strategies for patients with IIM because of the lack of large-scale, randomized, controlled studies. This review focuses primarily on our current management and treatment algorithms for IIM including the care of pediatric patients with juvenile DM. For this review, we conducted a search of PubMed and MEDLINE for articles published from January 1, 1970, to December 1, 2011, using the following search terms: idiopathic inflammatory myopathies, dermatomyositis, polymyositis, juvenile dermatomyositis, sporadic inclusion body myositis, inclusion body myositis, inflammatory myositis, myositis, myopathies, pathogenesis, therapy, and treatment. Studies published in English were selected for inclusion in our review as well as additional articles identified from bibliographies.
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Satoh M, Ceribelli A, Chan EKL. Common pathways of autoimmune inflammatory myopathies and genetic neuromuscular disorders. Clin Rev Allergy Immunol 2012; 42:16-25. [PMID: 22083460 DOI: 10.1007/s12016-011-8286-7] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
It has been shown that many hereditary motor neuron diseases are caused by mutation of RNA processing enzymes. Survival of motor neuron 1 (SMN1) is well-known as a causative gene for spinal muscular atrophy (SMA) and mutations of glycyl- and tyrosyl-tRNA synthetases are identified as a cause of distal SMA and Charcot-Marie-Tooth disease. Why and how the dysfunction of these ubiquitously expressed genes involved in RNA processing can cause a specific neurological disorder is not well understood. Interestingly, SMN complex has been identified recently as a new target of autoantibodies in polymyositis (PM). Autoantibodies in systemic rheumatic diseases are clinically useful biomarkers associated with a particular diagnosis, subset of a disease, or certain clinical characteristics. Many autoantibodies produced in patients with polymyositis/dermatomyositis (PM/DM) target RNA-protein complexes such as aminoacyl tRNA synthetases. It is interesting to note these same RNA-protein complexes recognized by autoantibodies in PM/DM are also responsible for genetic neuromuscular disease. Certain RNA-protein complexes are also targets of autoantibodies in paraneoplastic neurological disorders. Thus, there are several interesting associations between RNA-processing enzymes and neuromuscular disorders. Although pathogenetic roles of autoantibodies to intracellular antigens are generally considered unlikely, understanding the mechanisms of antigen selection in a particular disease and specific neurological symptoms caused by disruption of ubiquitous RNA-processing enzyme may help identify a common path in genetic neuromuscular disorders and autoimmunity in inflammatory myopathies.
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Affiliation(s)
- Minoru Satoh
- Division of Rheumatology and Clinical Immunology, Department of Medicine, University of Florida, Gainesville, FL 32610-0221, USA.
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Stübgen JP. Targeted immunotherapy trials for idiopathic inflammatory myopathies. J Neurol 2012; 260:368-85. [DOI: 10.1007/s00415-012-6590-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2012] [Revised: 06/11/2012] [Accepted: 06/12/2012] [Indexed: 12/13/2022]
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Harms MB, Sommerville RB, Allred P, Bell S, Ma D, Cooper P, Lopate G, Pestronk A, Weihl CC, Baloh RH. Exome sequencing reveals DNAJB6 mutations in dominantly-inherited myopathy. Ann Neurol 2012; 71:407-16. [PMID: 22334415 DOI: 10.1002/ana.22683] [Citation(s) in RCA: 127] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2011] [Revised: 10/23/2011] [Accepted: 11/18/2011] [Indexed: 12/19/2022]
Abstract
OBJECTIVE To identify the causative gene in an autosomal dominant limb-girdle muscular dystrophy (LGMD) with skeletal muscle vacuoles. METHODS Exome sequencing was used to identify candidate mutations in the studied pedigree. Genome-wide linkage was then used to narrow the list of candidates to a single disease-associated mutation. Additional pedigrees with dominant or sporadic myopathy were screened for mutations in the same gene (DNAJB6) using exome sequencing. Skeletal muscle from affected patients was evaluated with histochemistry and immunohistochemical stains for dystrophy-related proteins, SMI-31, TDP43, and DNAJB6. RESULTS Exome analysis in 3 affected individuals from a family with dominant LGMD and vacuolar pathology identified novel candidate mutations in 22 genes. Linkage analysis excluded all variants except a Phe93Leu mutation in the G/F domain of the DNAJB6 gene, which resides within the LGMD locus at 7q36. Analysis of exome sequencing data from other pedigrees with dominant myopathy identified a second G/F domain mutation (Pro96Arg) in DNAJB6. Affected muscle showed mild dystrophic changes, vacuoles, and abnormal aggregation of proteins, including TDP-43 and DNAJB6 itself. INTERPRETATION Mutations within the G/F domain of DNAJB6 are a novel cause of dominantly-inherited myopathy. DNAJB6 is a member of the HSP40/DNAJ family of molecular co-chaperones tasked with protecting client proteins from irreversible aggregation during protein synthesis or during times of cellular stress. The abnormal accumulation of several proteins in patient muscle, including DNAJB6 itself, suggest that DNAJB6 function is compromised by the identified G/F domain mutations.
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Affiliation(s)
- Matthew B Harms
- Department of Neurology, Hope Center for Neurological Diseases, Washington University School of Medicine, St. Louis, MO 63110, USA
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Milisenda JC, Prieto-González S, Grau JM. Miositis con cuerpos de inclusión (forma esporádica). ACTA ACUST UNITED AC 2012. [DOI: 10.1016/j.semreu.2011.10.003] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Abstract
The different autoimmune myopathies-for example, dermatomyositis, polymyositis, and immune-mediated necrotizing myopathies (IMNM)-have unique muscle biopsy findings, but they also share specific clinical features, such as proximal muscle weakness and elevated serum levels of muscle enzymes. Furthermore, around 60% of patients with autoimmune myopathy have been shown to have a myositis-specific autoantibody, each of which is associated with a distinct clinical phenotype. The typical clinical presentations of the autoimmune myopathies are reviewed here, and the different myositis-specific autoantibodies, including the anti-synthetase antibodies, dermatomyositis-associated antibodies, and IMNM-associated antibodies, are discussed in detail. This Review also focuses on a newly recognized form of IMNM that is associated with statin use and the production of autoantibodies that recognize 3-hydroxy-3-methylglutaryl-coenzyme A reductase, the pharmacological target of statins. The contribution of interferon signaling to the development of dermatomyositis and the potential link between malignancies and the initiation of autoimmune myopathies are also assessed.
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